Paris - Argentina formally ended its search on Thursday for a submarine that went missing with 44 people aboard. Here are the most deadly submarine disasters over the past six decades.Argentina's San Juan, 44 lostThe San Juan, a 34-year-old German-built diesel-electric sub, goes missing with 44 crew aboard in the South Atlantic in mid-November. In its final communication, the submarine reports it has overcome a mechanical breakdown resulting from a short circuit due to the entry of water via the vessel's snorkel.Three hours later, a noise similar to an explosion is recorded 48km from where the crew had given its last report and on the same path the sub would have taken had it been returning to base.On Thursday the navy announces their mission has shifted from one of rescue to recovery, concluding no one could have survived on the missing sub for two weeks. Russia's Kursk, 118 dieIn August 2000 Russia's northern fleet nuclear submarine Kursk catches fire and explodes underwater while conducting war games.Russian authorities controversially refuse help from British and Norwegian naval vessels, and all 118 sailors on board the submarine are killed.Most die instantly but some survive for several days – with a few keeping heart-breaking diaries written in blood to their loved ones – before suffocating.It is the Russian navy's worst-ever disaster.Chinese navy, all 70 killedSeventy Chinese naval officers and crew are killed, apparently suffocated, in an accident on a Ming-class submarine conducting exercises east of the Neichangshan islands in May 2003.State media says the military was examining human error as a cause, including the mistaken shutting off of crucial exhaust valves, and the possibility of a chemical gas leak.The government says only there were "mechanical problems".Fire on Soviet vessel, 42 dieIn April 1989 a fire following a short circuit breaks out on board a Soviet nuclear submarine, the Komsomolets, while it is in international waters 500km from Norway.The crew is not able to put out the fire and quickly brings the vessel to the surface. Dozens dive into the glacial waters to escape, only a few taking to lifeboats. Some drown but most of the 42 dead are taken down in the submarine when it sinks. Twenty-seven people survive.1960s: Deadly decadeIn April 1963 the USS Thresher sinks with 129 people aboard off Cape Cod some 400km from the northeastern US coast. It is the first American nuclear submarine lost at sea.Ninety-nine sailors die in May 1968 in another American nuclear submarine, the Scorpion, which disappears in the Atlantic, probably sunk by one of its torpedoes.Also in 1968 the Soviet K-129 submarine armed with three nuclear missiles disappears with its 98 crew some 2 500km from Hawaii in the North Pacific. The United States later finds the wreck 5 000m below the surface and organises its recovery in a covert operation in 1974.1968 was marked by two other submarine disappearances. The Dakar, an Israeli vessel carrying out its maiden voyage with 69 men on board, disappears and is only found off the Greek island of Crete in 1999.And the Minerve, the jewel of France's navy, disappears off Toulon in southern France with 52 sailors on board.